HYPO-BL: Breast Lymphoedema and Radiation Treatment Randomised Controlled Trial – Ultra versus Moderate Breast Hypofractionation Radiation Treatment

After breast cancer surgery, most women receive radiotherapy to reduce the risk of the cancer coming back. Radiation can sometimes cause the breast tissue to become swollen or puffy — a condition called breast oedema or lymphoedema — and this can affect appearance, comfort, and quality of life. A newer, shorter radiotherapy schedule (called ultra-hypofractionation, 5 treatments over 1 week) may be just as effective as the standard 15-treatment schedule while being more convenient. However, it is not yet clear whether the two schedules cause the same amount of breast swelling. This study will measure breast tissue water content using a painless, handheld device before and after treatment to objectively compare swelling between the two schedules. Participants will be followed for 5 years to also assess quality of life, cosmetic outcomes, and cancer control. You may be eligible if you are a woman aged 50 or older with early-stage breast cancer (including DCIS) who has had breast-conserving surgery (a lumpectomy) with clear margins and does not require lymph node radiation. Women with a history of previous breast cancer, breast implants, or reconstructive surgery are not eligible.